While petrol or diesel is charged by the litre, a variety of companies running electric charging points deploy myriad pricing structures. Dozens of different tariffs exist, prompting the Department for Transport to launch a review in an attempt to simplify the system for consumers.

Ecotricity, which used to offer free charging to encourage the take up of electric cars, will change to its new tariff from tomorrow. Motorists will have to pay £3 connection fee and then a further 17 pence for every unit of electricity used (kWh). Previously the company charged a flat fee of £6 for 30 minutes of charge.

Ecotricity insists the price change will benefit customers but Zap-Map, a website which offers a consumer guide to charging points, has estimated that for a Nissan Leaf, the cost of charging it for 30 minutes will rise from £6 to £7.08.

Motorists have complained at the pricing change. One posted on the Zap-Map website: “He [Dale Vince] has now kicked his loyal customers in the teeth with a ridiculous price rise to £7.25 for the same amount of energy.

“He obviously wants to put all his limited resources into Green Gas and his football team.”

The RAC Foundation, the motoring think tank, estimates it will cost about 9p a mile to run a Nissan Leaf, about the same as the cost of an efficient petrol driven car. Zap-Map’s own analysis suggests it will still be cheaper to run an electric vehicle than an equivalent petrol or diesel driven car.